<template>
  <div class="todo-footer" v-if="total">
    <label>
      <input type="checkbox" :checked="isAll" @change="checkAll"/>
    </label>
    <span>
      <!-- <span>已完成{{ doneTotal }}</span> / 全部{{ todos.length }} -->
      <span>已完成{{ doneTotal }}</span> / 全部{{ total }}
    </span>
    <button class="btn btn-danger">清除已完成任务</button>
  </div>
</template>

<script>
export default {
  name: "MyFooter",
  props: ["todos", "checkAllTodo"],
  computed: {
    isAll() {
      return this.total === this.doneTotal && this.total > 0
    },
    total() {
      return this.todos.length;
    },
    doneTotal() {
      // // 方法不高级
      // let i = 0;
      // this.todos.forEach(todo=>{
      //   if(todo.done) i++
      // })
      // return i

      // const x = this.todos.reduce((pre, curr) => {
      //   console.log("22", pre, curr);
      //   return pre + (curr.done ? 1 : 0);
      // }, 0);

      return this.todos.reduce((pre, curr) => pre + (curr.done ? 1 : 0), 0);
    },
  },
  methods:{
    checkAll(e) {
      this.checkAllTodo(e.target.checked)
    }
  }
};
</script>

<style scoped>
/*footer*/
.todo-footer {
  height: 40px;
  line-height: 40px;
  padding-left: 6px;
  margin-top: 5px;
}

.todo-footer label {
  display: inline-block;
  margin-right: 20px;
  cursor: pointer;
}

.todo-footer label input {
  position: relative;
  top: -1px;
  vertical-align: middle;
  margin-right: 5px;
}

.todo-footer button {
  float: right;
  margin-top: 5px;
}
</style>